abstract class Fisheye{
  /** source */
  src: HTMLImageElement | HTMLCanvasElement | HTMLVideoElement | null;

  /** ajast center */
  centerX: number;
  centerY: number;
  radius: number;

  /** GL canvas */
  canvas: HTMLCanvasElement;

  /** canvas size */
  width: number;
  height: number;

  destructor(): void;
  render(): void;
}

class Fisheye2Perspective extends Fisheye {
  /** direction of view */
  pitch: number;
  yaw: number;
  zoom: number;
  constructor();
  drag(type: "start" | "move", offsetX: number, offsetY: number): any;
}

class Fisheye2Equirectangular extends Fisheye{
  constructor();
}